Tunneling machine



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awrnwfll wa/ull/n/ United States Patent 3,231,310 TUNNELING MACIHNE Nicholas Santucci, Skokie, 11]., assignor to Santucci Construction (Jompany, Skokie, 111., a corporation of Illinois Filed Nov. 17, 1961, Ser. No. 153,120 6 Claims. (Cl. 299-56) This invention relates to earth moving equipment and is more specifically concerned with improvements in a machine for boring or digging a tunnel.

It is a general object of the invention to provide improvements in an earth moving or excavating machine which greatly facilitates the use of the machine in tunnel digging or boring operations and permits the removal of earth at a faster rate than possible with similar machines heretofore provided.

It is a more specific object of the invention to provide improvements in a tunneling machine of the type which comprises a main supporting frame movably mounted on a wheeled truck which is in turn carried on a track adapted to be moved forward as the tunneling progresses with the frame having a travelling chain carried on the periphery of a secondary frame disposed in a transverse plane at the front end of the main frame and a plurality of spaced excavating buckets arranged on the chain so as to pick up earth along a path which corresponds to the cross section of the tunnel with the buckets being inverted at the top of their path so as to dump the contents onto a traveling belt which is mounted on the main frame and which delivers the earth to the trailing end of the main frame where it may be loaded into a truck or other vehicle and removed from the vicinity of the machine or out of the tunnel.

A further object of the invention is to provide in a tunneling machine of the character described a transverse frame at the forward end of the machine with a track extending along the periphery thereof and having a traveling chain mounted on the track with a series of excavating buckets carried on the chain which are each provided with teeth for cutting into the earth as they traverse their path and with a pivoted bottom forming plate section which is swung to clean out the bucket when it is inverted at the top of its path so as to dump the contents therefrom.

It is another object of the invention to provide a tunneling machine which comprises a main frame mounted for sliding movement on a track supported wheeled truck, a vertically disposed cross frame mounted at the forward end of the main frame and having a peripheral track for an endless chain which carries a plurality of excavating buckets with the buckets having teeth on their free edges and being arranged on the chain so as to cut a path which corresponds to the cross section of the tunnel, a driven power shaft assembly extending lengthwise of the main frame, a driving connection between the power shaft and the bucket carrying chain, an excavating arm extending radially of the forward end of the power shaft and having teeth for cutting ahead of the cross frame in an area within the confines of the cross frame, and a traveling belt conveyor mounted on the main frame for receiving the excavated materials from the buckets and for carrying the same to the rear of the machine.

These and other objects and advantages of the invention will be apparent from a consideration of the machine which is shown by way of illustration in the accompanying drawings wherein:

FIGURES 1A and 1B are elevations, with portions shown diagrammatically and other portions omitted, of one side of a tunneling machine which incorporates therein the principal features of the invention;

FIGURE 2 is an elevation at the front end of the machine to an enlarged scale and with portions omitted and other portions shown diagrammatically;

FIGURE 3 is a rear end elevation of the machine to an enlarged scale;

FIGURE 4 is a cross section taken on the line 44 of FIGURE 1A, to an enlarged scale and with portions broken away or omitted;

FIGURE 5 is a view taken generally on the line 5-5 of FIGURE 1A and with portions broken away;

FIGURE 6 is a fragmentary cross section taken on the line 6-6 of FIGURE 5, to an enlarged scale and with portions broken away;

FIGURE 7 is a sectional view taken on the line 77 of FIGURE 2, to an enlarged scale;

FIGURE 8 is an elevational view taken on the line 88 of FIGURE 7 to a smaller scale;

FIGURE 9 is an elevational view taken on the line 9-9 of FIGURE 7 to a smaller scale;

FIGURE 10 is a cross section taken on the line 1010 of FIGURE 7 to a smaller scale;

FIGURE 11 is a fragmentary cross section taken on the line 1111 of FIGURE 9 to an enlarged scale; and

FIGURE 12 is a fragmentary section taken on the line 1212 of FIGURE 2 to an enlarged scale.

Referring to the drawings, there is illustrated a tunneling machine having embodied therein the principal features of the invention, which is adapted to bore or dig a tunnel of predetermined cross sectional dimensions and which has provisions for conveying material being removed to the rear of the machine so that it may be conveniently carried away by trucks, mine cars or similar conveyances.

The machine comprises briefly a supporting truck structure 10 (FIGURES 1A, 1B, and 2 and 5) which adapted to be mounted on a track section 11 and which carries in longitudinal slidable relation on the bed thereof a main frame 12 having mounted thereon a longitudinally extending drive shaft assembly 13 and associated operating mechanism. The main frame 12 supports at its forward end a head frame 14 on which there is carried a traveling bucket assembly 15, the frame 14 being disposed in a vertical transverse plane. The shaft 13 has a forward or end section which extends beyond the head 14 and carries a rotatable cutting or digging head 16. A longitudinally extending conveyor assembly 17 is mounted on the top portion of the main frame 12 and provided with a funnellike hopper 18 at the leading or digging end for receiving the dirt from the bucket assembly 15 and a corresponding or like hopper 19 at the trailing or discharge end into which dirt is delivered.

The truck 10 comprises longitudinally extending, generally rectangular main frame structure 21) (FIGURE 4) which includes laterally spaced side angle members 21 and 22 forming tracks for supporting in sliding relation on the truck 10 the main frame 12. The truck frame 20 supports three pairs of longitudinally spaced, flanged wheels 23, 24 and 25 with each pair of the wheels being mounted on transversely extending axles and the frame 20 carrying a suitable drive mechanism, such as an air motor, (not shown) which is connected by suitable drive means (not shown) with one or more of the axles for the supporting wheels 23, 24 and 25. The truck unit 10 is of standard track width and adapted to ride on a track section 11 which comprises longitudinally extending rails 26 and 27 and suitable connecting cross bars or plate members. The truck unit 10 and its associated drive mechanism constitute a commercially available unit which is adapted to the present machine by extending the supporting frame so as to provide rails 21 and 22 of the proper length for supporting the main frame 12 of the machine.

The truck unit 10 is also provided with an apparatus for raising the same to free the track unit 11 for removal and replacement. This apparatus comprises a pair of hydraulic cylinders 30 (FIGURES 1A, 4 and 5) which are laterally spaced at opposite ends of a cross beam 31 with the cross beam 31 being connected by suitable brackets or the like to the carriage frame structure at a point between the two leading sets of wheel assemblies 23 and 24. Each of the cylinders is vertically disposed and has a piston 32 with a foot forming plate 33 on the end thereof for engaging with the floor of the tunnel, when the apparatus is in use. The cylinders 30 are connected to the hydraulic system for operating the machine through a suitable line which includes the control valve 34 (FIGURE 5) mounted on the bracket 35 and having an operating handle 36 for controlling the cylinders 30. At its other end the truck frame side angle members 21 and 22 are connected to upright side members 37 and 37' of a vertically disposed end frame 38 by bracket members 39 and 39. The end frame 38 has a removable top section 40 (FIGURE 3) which includes a top cross brace member 41 of angular cross section and having its upstanding flange cut to correspond to the tunnel roof contour resulting from the operation of the bucket assembly 15. The side members 42 and 42 of the removable section 40 are telescopically connected to the bottom portions of the side members 37 and 37' of the frame. At the lower ends of the side frame members 37 and 37' short lengths of pipe 43 and 43' are provided which are adapted to receive in their open lower ends screw jacks 44 so that the entire end frame 38 may be raised by operation of the jacks 44 to brace the machine againstthe ceiling of the tunnel, and also hold the truck 10 against any movement on the track 11.

The main frame or movable section 12 of the machine comprises a pair of angle members forming side rails 45 and 46 (FIGURES 2, 4 and 5) which have the top horizontally disposed flanges connected by a base plate 47 for supporting the longitudinally extending drive shaft assembly 13 and its associated mechanism. The side rails 45 and 46 are provided along their bottom edges with angle bars 48 and 50 which have vertically disposed flanges secured to the vertical flanges of the side rails 45 and 46 and their horizontally disposed flanges extending beneath the lower edges of the side rails 21 and 22 on the truck frame structure 20 so as to prevent vertical separation of the main frame 12 from the truck frame 20, leaving the main frame free for longitudinal sliding movement on the truck frame. Relative movement between the main frame 12 and the truck unit 10 is provided for by a pair of longitudinally positioned hydraulic cylinders 51 and 52 which are pivotally mounted at 53 and 54 to anchor brackets 55 and 56, the latter being secured on the top of the base plate 47 and connected by an angle brace 57. The cylinders 51 and 52 have their pistons 58 and 59 pivotally connected to brackets 60 and 61 which are secured near the end of the truck body 20 and connected by a cross brace 62. The cylinders 51 and 52 are connected to the hydraulic system through the valve 34 so as to be operated by the valve control handle 63.

The shaft assembly 13 (FIGURES 1A and 5) which constitutes the drive shaft for the machine has a shaft section 64 at the front end of the machine which is supported in a longitudinally extending housing 65 having end supporting bracket formations of inverted V-shape form which are secured to the base plate 47 in longitudinally spaced relation and straddle a supply tank 68 for oil or other hydraulic fluid at the front end of the machine. The shaft section 64 is connected by a suitable coupling in axial alignment with the output shaft 69 of a gear reduction unit 70 which has its input shaft coupled to the drive shaft 71 of a transmission 72 and an associated clutch mechanism 73 connected in line therewith. The transmission 72 is provided with an operating handle 74 and the clutch 73 is provided with an operating linkage 75 so that both are manually controlled. The input shaft section 76 of the clutch 73 is coupled in axial alignment with the shaft 77 of a drive motor 78. The

shaft section 76 carries a sprocket 79 which is connected by the chain 80 with the drive sprocket 81 on a pump 82, the latter being supported by a bracket 83 extending upwardly of the side frame member base plate 46. The pump 82 supplies pressure in the hydraulic line. The motor 78 is, of course, connected by a suitable cable with a source of electric current.

The digging and soil removing mechanism at the front of the machine comprises a bucket assembly 15 (FIG- URES 1A, 2, 5 and 7 to 11), its supporting framework 14 and a cutting head mechanism 16 on the end of the power shaft assembly 13. The cutting head mechanism 16 (FIGURES 1A, 2 and 5) comprises a hub 84 with a series of three equally spaced arms 85 of identical construction which extend radially therefrom and are inclined slightly in the forward direction. The arms 85 each comprise a tubular main section and a telescoping extension 86 which may be adjusted relative to the main section for a particular digging operation. Each of the arms 85 carries a series of spaced cutting knife elements 87. The knives or fingers 87 are of generally rectangular shape and are secured at their base on the tubular arm members so that they extend in a tangential plane for wardly thereof with the forward edges being sharpened so that as the head 16 is rotated by operation of the shaft assembly 13 the knives 87 cut into the earth ahead of the machine. While the arms 85 may be extended they will be adjusted in length normally so that the circular cutting area of the head is within the cross sectional area desired for the tunnel being dug. This permits the cross section of the tunnel to be determined by the operation of the excavating buckets as hereinafter described.

The frame 14 for mounting the bucket assembly is detachably supported on the forward end of the main frame 12 of the machine. The bucket frame 14 comprises a track forming frame member 88 which is H-shaped in cross section and which has a generally circular configuration as shown in FIGURE 2 or any other similar configuration depending upon the cross section of the tunnel to be dug. The frame member 88 (FIGURES 2, 7 and 8) comprises front and back plates 89 and 90 which are connected by a cross web 91 extending between the two spaced plates. The entire frame is removably attached to the main frame 12 of the machine by bolting the same at the upper portion thereof to connecting bracket members 92 and 93 at the upper ends of the upwardly and forwardly inclined side brace members 94 and 95. The latter are in the form of angle bars rigidly secured at the lower ends to the base plate 47 on the main frame 12 by angle brackets 96 and 97. The frame member 88 is also secured at the lower end thereof by bolting the back plate 90 to a pair of laterally spaced bracket plates 98 which depend from an end cross member 99 on the main frame 12.

The bucket frame 88 is provided with a series of spaced track forming rollers 100 which are mounted on support shafts or pins 101 extending between the plates 89 and 90 with the rollers 100 being flanged or grooved to form a track-like support for the links of a bucket chain 102. The bucket chain 102 comprises a series of U-shaped link members 103 connected by cross pins 104. The chain 102 carries in equally spaced relation thereon a plurality of excavating buckets 105. Each of the buckets 105 is connected to the chain 102 by an angle bracket member 106 having one leg 107 bolted to a chain link 103 and the other leg 108 bolted to the inside wall of a bucket 105.

The buckets 105 (FIGURES 7 to 11) each comprise a body forming plate bent as shown in FIGURES 7 t0 9 into generally U-shape with the back or inside wall portion 109 extending somewhat higher at the inner end than the front or outside wall portion 110 and with the latter being inclined upwardly somewhat and the two walls meeting at a rounded end section 111 which is also inclined in the upward direction with the inclination being somewhat less than at the inner end of the front plate portion 110. The front wall portion 110 and the end wall portion 111 carry a series of spaced cutting teeth 112 each of which comprises a generally rectangular plate-like member 113 having an outer knife edge and attached to the bucket wall by a brace member or bracket 114 of angular shape. The teeth 112 are inclined at somewhat different angles with the outward inclination increasing from the inner end of the side wall to the end wall section 111. The top and inner end of the bucket as viewed in FIGURE 9 remain open. A hinged bottom plate member 115 is provided for the bucket which has a main section conforming generally to the shape of the bottom opening of the bucket and somewhat smaller so as to be swingable therein. The plate 115 has a tail section 116 of generally triangular shape which is separated from the main section by a cross plate 117 of rather shallow height. The bottom plate member 115 is hinged to the bucket by means of a cross pin or bolt 118 which extends through a bearing housing 120 formed on the bottom side of the plate 115 beneath the cross plate 117. The bottom plate member 115 is supported in bottom forming position in the bucket by stop lugs 121 which extend inwardly from the bottom edge of the side wall sections 189 and 110. The bottom plate member 115 is urged in the direction of the stop lugs 121 by a pair of torsion springs 122, each of which has one end 123 hooked into a recess 124 in the lower edge of the side plate and the other end thereof 125 extending beneath the tail piece 116 with the coil of the spring 122 being supported on the pivot bolt 118. The side wall 110 may be provided with a pair of holes 126 for drainage purposes. Each bucket 105 travels throughout a predetermined portion of its path with the bottom plate 115 in proper position for receiving dirt in the bucket. The path of travel of the buckets is, of course, determined by the shape of the frame 88.

A tripping device (FIGURE 12) isprovided on the frame 88 near the upper point traversed by the buckets 105 for swinging the bottom plate 115 to dumping or bucket cleaning position at a predetermined point in the path of travel of the bucket so as to insure that the bucket contents will be dumped into the hopper 18 at the forward end of the horizontally disposed belt conveyor assembly 17. The trip arrangement comprises a channel-shaped or U-shaped arm member 130 which is pivotally mounted at 131 on the bottom face of the cross web 91 near the upper end of the bucket frame 88. The arm 130 carries a cam roller 132 mounted on a shaft 133 which extends between the two legs of the U-shaped member 130. The member 138 extends through a slot 134 in the front side wall 89 of the frame 88 so as to normally project into the path of the oncoming tail pieces 116 on the buckets 185. Outward movement of the trip member 130 is opposed by a tension spring 136 anchored at 137 on the plate 91 and connected at 138 to the inner leg of the member 138. As the buckets move around the point where the trip member 138 is located, the tail piece 116 moves the trip member 130 outwardly until it extends in a generally normal direction relative to the front plate .89 as indicated in dotted line in FIGURE 12 after which the plate 115 is forced to swing about the pivot 118 to an angle sufficient to clean the dirt from the bucket if it is stuck therein and dumps the same into the hopper 18 of the conveyor 17.

The bucket chain 182 is driven by a sprocket 140 (FIGURES 2, 5 and 6) which is mounted on a stub shaft 141 journaled in a bearing bracket 142 mounted on the outside face of the side rail 45 of the main frame 12 adjacent the front end thereof. The stub shaft 141 carries a sprocket 143 which is connected by the chain 144 with a drive sprocket 145 on the front end section 64 of the main drive shaft assembly 13. This drive mechanism is covered by a housing 146.

The conveyor assembly 17 (FIGURES 1 to 4) is driven by a separate motor so that it operates independently of 6 the rest of the machine. Also, it is mounted so that it may be readily removed from the machine. It comprises a relatively wide belt 147 supported on a longitudinally extending frame 148. The frame 148 has laterally spaced, oppositely facing side channel members 150 and 151 which are connected by suitable cross bracing 152. The belt 147 is supported along its upper run and intermediate the ends of the frame 148 so that it forms a concave cross section, providing an upwardly facing support for conveying the material delivered to the hopper 18. It is supported on longitudinally spaced roller assemblies which comprise inclined side rollers 153 and 154 and a center roller 155. The side rollers 153 and 154 are supported on pairs of end bearing brackets 156, 156' and 157, 157' and the center roller 155 is supported on a pair of bearing brackets 158, 158'. The outermost bearing brackets 156 and 157 are mounted on the top legs'of the side channels 150 and 151 and the inner bearing brackets 158, 158, 156' and 157' are mounted on the cross bracing 152. Rollers 160 for supporting the belt 147 along its lower run are mounted at intervals along the bottom edges of the side channels 150 and 151 on pairs of depending bearing brackets 161, 161. At the receiving end of the conveyor 17 the belt 147 passes beneath the hopper 18 and is supported on a single end roller 162 which is mounted in end bearings 163, 163' on the ends of the conveyor frame 148. Likewise, at the rear end of the frame 148 the belt 147 is supported on a single roller 164 adjacent the discharge hopper 19. The roller 164 has its shaft 165 mounted in suitable end bearings and carries at one end a drive sprocket 166. The drive sprocket 166 is connected by a drive chain 167 with the sprocket 168 on the end of the output shaft 178 of a drive motor 171. The motor 171 is mounted on a support plate 172 extending between a pair of depending bracket members 173, 173 forming a supporting frame for the motor which is independently supplied with current so as to drive the belt 147. The hopper 19 (FIGURES 1B and 3) which is arranged at the delivery end of the conveyor assembly and which receives the excavated material from the belt 147 as it passes over the roller 164 has an open bottom 174 in which is mounted a downwardly inclined discharge plate 175. The plate 175 may be pivotally mounted if desired so as to discharge the dirt on either side of the conveyor. The conveyor frame 148 is bolted to the upwardly inclined front frame brace members 94 and 95 by means of brackets 176 and 176. At the rear end of the main frame 12 of the machine the conveyor frame 148 is bolted to the upper ends of a pair of upstanding end frame forming members 177 and 177' which are connected at their lower ends to the side rail members 45 and 46 of the main frame 12.

The machine is braced against lateral movement when in operation in a tunnel by means of screw jacks 178 and 178' (FIGURES 1A, 3 and 5) at the rear end of the machine. Each of these jacks has a base 180 adapted to seat in a slot or recess 181 provided in a bracket 182 secured to the side rail members 21 and 22 of the frame 20 of the truck 10. It is braced at the front end of the machine by screw jacks 183 and 183' (FIGURES 1A and 4) of the same character which have a base plate 184 adapted to seat in a recess 185 in a bracket 186 on the ends of the cross beam 31.

A top bracing structure may be provided at the front of the machine which comprises a cross frame 187 (FIG- URES 1A and 4) of inverted U-shape with the legs 188 and 188 adapted to be bolted to the inclined side braces 94 and 95 and having a vertically adjustable upper section which comprises a curved plate 190 on a framework 191 which is mounted on the end of the piston 192 of the vertically disposed hydraulic cylinder 193 mounted on the top member of the cross frame 187. The top brace plate 190 has the same contour as the upper or ceiling cutting portion of the path of the buckets 105 so as to be movable against the ceiling after the cutting occurs for bracing the machine.

In operating the machine, the entrance end of the tunnel is excavated by other means a suflicient distance to receive the machine. The machine, with a cross frame 14 of the desired shape and with the cutting head arms adjusted to cut in an area within the confines of the cross frame, is positioned as shown in FIGURE 1A with the main frame 12 in the retracted position on the truck 10, the latter being supported on the track section 11. The rear end of the truck frame 20 is braced between the roof and the floor of the tunnel by extending the jacks 44. The motor 78 is started which turns the shaft assembly 13 and also the motor 171 which operates the conveyor 17. The clutch 73 is operated to connect the shaft assembly 13 to the power shaft of the motor 78 so that the forward shaft section 64 rotates. This turns the cutting head 16 and also operates the chain 102 which carries the buckets 105. The cylinders 51 and 52 are actuated by operation of the valve 34 and manual control lever 63 to move the frame 12 forwardly as the material is cut by the head 16 and the buckets 105. The excavated material is delivered by the buckets 105 to the hopper 18 and is carried by the belt 147 to the discharge hopper 19 at the end of the machine. When the frame 12 has been moved a predetermined distance forwardly on the truck the cutting operation is discontinued and the machine is moved forwardly. The frame 12 is retracted on the truck 10 by operation of the cylinders 51 and 52. The cylinders 30 are actuated through valve 34 and manual control lever 36 to extend the pistons 32 downwardly and raise the entire forward end of the machine so the truck 10 is lifted free of the rail section 11. The rail section 11 is then moved forwardly to a new position. The cylinders 30 are operated to drop the machine onto the track section 11. The jacks 44 are raised to release the rear end of the truck and the truck is moved forward under its own power to position the cutting head 16 and the bucket assembly for further excavating operations. The jacks 178, 178' and 183, 183' are, of course, released when the truck 10 is to be moved.

The top brace structure 191 at the forward end of the machine may be used when desired to hold ceiling braces in position depending upon the character of the material being excavated.

While particular materials and specific details of construction have been referred to in describing the illus trated form of the machine, it will be understood that other materials and equivalent details of construction may be resorted to within the spirit of the invention.

I claim:

1. -In a tunneling machine having a supporting truck with a horizontally disposed, longitudinally extending track, a main frame slidably mounted on said track for movement in the direction of travel of said truck, and power means for sliding said main frame along said track, a power shaft assembly supported lengthwise on said main frame, power means to rotate said shaft assembly, an excavating device secured on the forward end of said shaft assembly and rotating therewith which comprises a cutter head having a plurality of radially extending arms, excavating teeth spaced along the arms and having cutting blades extending forwardly thereof, so as to cut in a predetermined path, a vertical cross frame detachably mounted for ready removal and replacement at the forward end of said main frame and extending in a generally vertical transverse plane immediately back of said cutter head, said cross frame having a periphery which corresponds substantially to the periphery of the desired cross section of the tunnel which the machine is adapted to excavate, a track extending about said periphery, an endless carrier mounted to travel on said track, a plurality of excavating buckets mounted in spaced outwardly extending relation on said carrier so as to travel in a path about the periphery of said cross frame, said buckets each having an open side facing in the direction of travel and a plurality of excavating teeth spaced around the periphery of said open side and projecting outwardly thereof, whereby said buckets are adapted to excavate material along said path and also to pick up material excavated by said cutter head, said cutter head having its arms extending so that the path cut by said head is within the confines of the cutting path of the buckets, and drive means connecting said carrier with said shaft assembly so as to move said buckets in said path.

2. In a machine for excavating a tunnel of predetermined cross section, which is characterized by a wheeled truck structure adapted to be mounted on a length of track and having power means to move the same along the track, an elongate main frame mounted on said truck structure for sliding movement lengthwise thereof and power means to advance and retract said main frame on said truck structure, a power shaft mounted to extend lengthwise of said main frame and power means connected to said shaft to rotate said shaft, a readily detachable and replaceable cross frame mounted at the forward end of said main frame, said cross frame having an outwardly facing track formation extending about its periphery, an endless chain mounted for movement on said track formation and means for connecting said power shaft in driving relation with said chain, excavating buckets each having an open side and excavating teeth spaced arount said open side, said buckets being secured in spaced relation on said chain with the open side facing in the direction of advance of the buckets and with the teeth extending outwardly thereof so as to cut a path corresponding to the periphery of said predetermined cross section with excavated material being picked up by the bucket at the bottom of its path and carried upwardly to a dumping point where the bucket is inverted at the top of said cross frame and said buckets being mounted to excavate material outside the periphery of said cross frame.

3. In -a machine for excavating a tunnel, which is characterized by a truck structure adapted to be mounted on a length of track and having power means to move the same along the track, said truck structure including a longitudinally extending track formation, an elongate main frame mounted on the track formation for sliding movement lengthwise of the truck, and power means for sliding said main frame on said track, a power shaft mounted to extend lengthwise of said main frame and power means connected to said shaft to rotate said shaft, a removably mounted cross frame at the forward end of said main frame, said cross frame having a track formation about its periphery which extends in a path corresponding to the desired cross sectional contour of the tunnel, an endless chain mounted for movement on said cross frame track, means connecting said power shaft in driving relation with said chain, a plurality of excavating buckets each having an open side and excavating teeth spaced around said open side, each said bucket being mounted on said chain so that the open side faces in the direction of advance of the bucket and the outermost teeth cut a path defining the inside wall of the tunnel with the excavated material being directed by the excavating teeth into the bucket which carries it upwardly to a dumping point at the top of said cross frame where the position of the bucket is inverted so as to dump the material, said main frame having upwardly directed cross frames at the front and rear ends thereof, and a longitudinally extending traveling belt conveyor supported on said cross frames with its forward end extending beneath the top portion of the path of travel of said buckets so as to receive excavated material dumped from the buckets.

4. In a tunneling machine having a wheeled truck, a track section supporting said truck, a longitudinally extending main frame movably mounted on said truck, and

power means for moving the main frame relative to the truck, a secondary frame disposed in a transverse plane at the leading end of said main frame, and a traveling chain carried on the periphery of said secondary frame, power drive means for said chain, a plurality of spaced excavating buckets mounted on said chain, said buckets each having an open top and an open side with cutting blades mounted on the edges of the open top, said buckets being mounted on the chain so that the open top faces in the direction of travel of the bucket and the open side faces inwardly of the path of the chain whereby said cutting blades extend outwardly of the periphery of said secondary frame and cut a path which determines the cross section of the tunnel, said buckets being mounted to pick up excavated material at the bottom of their path and being inverted as they traverse the top of their path so as to dump their contents, said buckets each having side walls and a pivotally mounted bottom forming plate member and means for swinging the bottom members of successive buckets between the side walls thereof as said buckets reach the top of their path thereby to force the contents of the buckets from between the side walls and dump the same, and means for receiving the contents of the buckets and conveying the same to the trailing end of the machine.

5. In a tunneling machine having a wheeled truck with a track formation thereon, a track section supporting said truck, a longitudinally extending main frame movably mounted on said track formation, and power means for moving said main frame along said track, a secondary frame disposed in a transverse plane at the leading end of said main frame, a traveling chain carried on a track forming means extending about the periphery of said secondary frame, means for driving said chain, a plurality of spaced excavating buckets each mounted on said chain so as to extend forwardly of said chain, said buckets each having the top and an adjoining side open with cutting fingers extending from the top edge, each of said buckets being arranged on said chain so that the open top faces in the direction of advance of the chain and the fingers cut a path which determines the cross section of the tunnel, said buckets being adapted to pick up material at the bottom of their path and being inverter as they advance at the top of their path so as to dump their contents through the inverted open top thereof, and conveyor means positioned to receive the dumped contents of the buckets and convey the same to the trailing end of the machine, said buckets each having a bottom forming plate member pivotally mounted for movement within the open side and top thereof, spring means holding said bottom member in a normal bottom forming position and a trip member at a fixed point along the top portion of the path of the buckets for swinging said bottom member to clear the bucket of its contents as it reaches dumping position.

6. In a tunnel digging machine having a main frame and a cross frame at the forward end thereof, an endless traveling chain mounted on the periphery of the cross frame, power means for driving said chain, a plurality of excavating buckets carried on said chain, each of said buckets comprising a plate-like member bent into U- shape and forming a body member therefor with an open side and an open top adjoining each other, bracket means securing said body member to said chain with the open side adjoining open top facing inwardly of the path of the chain and in the direction of advance of the chain, respectively, a bottom forming member pivoted between the legs of the body member at a bottom forming side thereof with a portion extending out of the said open side, spring means urging the bottom member into bottom forming position, stop means for limiting the movement of said bottom member to a bottom forming position within the body member, cam means adjacent the top of said cross frame for engaging the extending portion of said bottom forming member so as to swing the bottom forming member tthrough the body member toward the open side of the bucket and thereby empty the bucket, and conveyor means mounted on said main frame for receiving material delivered 'by the buckets and conveying the same toward the rear end of said main frame.

References Cited by the Examiner UNITED STATES PATENTS 857,396 6/1907 Hammond 37191 X 1,044,279 11/1912 Smith 3797 1,193,826 8/1916 Ruth 198-144 1,478,466 12/ 1923 Anderson 26215 1,581,318 4/1926 Lium 3797 1,588,638 6/1926 White 198-444 1,764,949 6/ 1930 George 37191 X 1,912,743 6/ 1933 Vaughn 37191 2,083,834 6/ 1937 Galuppo et a1. 26215 2,578,058 12/1951 Graham et a1. 3797 2,833,531 5/1958 Joy 26211 2,864,599 12/1958 Mason 262-45 2,937,859 5/1960 Jackson 26215 2,988,348 6/ 1961 Robbins 262-45 CHARLES E. OCONNELL, Primary Examiner.

BENJAMIN BENDETT, BENJAMIN HERSH,

Examiners, 

1. IN A TUNNELING MACHINE HAVING A SUPPORTING TRUCK WITH A HORIZONTALLY DISPOSED LONGITUDINALLY EXTENDING TRACK, A MAIN FRAME SLIDABLY MOUNTED ON SAID TRACK FOR MOVEMENT IN THE DIRECTION OF TRAVEL OF SAID TRUCK, AND POWER MEANS FOR SLIDING SAID MAIN FRAME ALONG SAID TRACK, A POWER SHAFT ASSEMBLY SUPPORTED LENGTHWISE ON SAID MAIN FRAME, POWER MEANS TO ROTATE SAID SHAFT ASSSEMBLY, AN EXCAVATING DEVICE SECURED ON THE FORWARD END OF SAID SHAFT ASSEMBLY AND ROTATING THEREWITH WHICH COMPRISES A CUTTER HEAD HAVING A PLURALITY OR RADIALLY EXTENDING ARMS, EXCAVATING TEETH SPACED ALONG THE ARMS AND HAVING CUTTING BLADES EXTENDING FORWARDLY THEREOF, SO AS TO CUT IN A PREDETERMINED PATH, A VERTICAL CROSS FRAME DETACHABLY MOUNTED FOR READY REMOVAL AND REPLACEMENT AT THE FORWARD END OF SAID MAIN FRAME AND EXTENDING IN A GENERALLY VERTICAL TRANSVERSE PLANE IMMEDIATELY BACK OF SAID CUTTER HEAD, SAID CROSS FRAME HAVING A PERIPHERY WHICH CORRESPONDS SUBSTANTIALLY TO THE PERIPHERY OF THE DESIRED CROSS SECTION OF THE TUNNEL WHICH THE MACHINE IS ADAPTED TO EXCAVATE, A TRACK EXTENDING ABOUT SAID PERIPHERY, AN ENDLESS CARRIER MOUNTED TO TRAVEL ON SAID TRACK, A PLURALITY OF EXCAVATING BUCKETS MOUNTED IN SPACED OUTWARDLY EXTENDING RELATION ON SAID CARRIER SO AS TO TRAVEL IN A PATH OF THE PERIPHERY OF SAID CROSS FRAME, SAID BUCKETS EACH HAVING AN OPEN SIDE FACING IN THE DIRECTION OF TRAVEL AND A PLURALITY OF EXCAVATING TEETH SPACED AROUND THE PERIPHERY OF SAID OPEN SIDE AND PROJECTING OUTWARDLY THEREOF, WHEREBY SAID BUCKETS ARE ADAPTED TO EXCAVATE MATERIAL ALONG SAID PATH AND ALSO TO PICK UP MATERIAL EXCAVATE BY SAID CUTTER HEAD, SAID CUTTER HEAD HAVING ITS ARM EXTENDING SO THAT THE PATH CUT BY SAID HEAD IS WITHIN THE CONFINES OF THE CUTTING PATH OF THE BUCKETS, AND DRIVE MEANS CONNECTING SAID CARRIER WITH SAID SHAFT ASSEMBLY SO AS TO MOVE SAID BUCKETS IN SAID PATH. 